Knucklehead crank pins

Hi Steve Slaminko here,

Well I'm retired again for the 3rd time so the 1938 Knuck is back in the building line-up. Upon tear down, I discovered it has the correct flywheels for 1938 but the crank pin is the later stepped type. Did the flywheels have to be modified to accept this crankpin or are the 1936 - 1939 pin #348-36 and the #348-40 stepped pin interchangeable if you use the correct rod cages and bearings?